End-to-End Encrypted Note Sync Between Chrome and Firefox

FreelyMemo's notes are local-first by default: nothing leaves your device unless you turn sync on. But if you use both Chrome and Firefox — a work laptop and a personal one, say — you'll eventually want the same notes on both. That's what end-to-end encrypted note sync between Chrome and Firefox is for, and it's one of the features unlocked in FreelyMemo Pro.

How end-to-end encrypted note sync between Chrome and Firefox works

When you enable sync, your notes are encrypted locally with AES-256-GCM using a key derived from your license key via PBKDF2 with one million iterations. That key derivation happens on your device — we never have access to it. By the time anything reaches our servers, it's already ciphertext. Our infrastructure, hosted by Supabase, stores encrypted blobs, device identifiers, sync timestamps, and a hash of your license key for grouping devices — never your license key itself, never your notes in readable form.

This is a genuinely zero-knowledge setup, not just a marketing label: even if our database were fully exposed, an attacker would see encrypted blobs, not your notes. What's explicitly not stored on our servers, ever, is your license key itself, your notes in readable form, or any record of the pages you were browsing.

How syncing actually works

Once it's on, FreelyMemo checks for changes and syncs automatically about every 60 seconds — you don't need to trigger it manually or remember to hit "save." One Pro license covers two seats, so the same license key that unlocks Pro on Chrome also unlocks it on Firefox, and that's what ties your two installs together for sync.

You can turn sync off at any time. Your notes stay right where they are, on your local device. Anything already stored server-side (still encrypted) is kept for 30 days in case you turn sync back on, then deleted permanently.

One thing worth being explicit about: sync only affects notes on devices where it's turned on with the same license key. If you install FreelyMemo on a third device without entering that key, it starts with its own local, unsynced notes — sync is opt-in per install, not automatic just because the extension is present.

A practical example

You jot a note on your work laptop in Chrome during the day — a meeting follow-up, a link, a half-formed idea. That evening, on your personal laptop running Firefox, the same note is there, because sync picked it up automatically in the background. Neither FreelyMemo nor anyone with access to our servers can read what's in that note along the way — only your two devices, with your license key, can decrypt it.

Sync is one part of the Pro tier; if you also want your notes out of the extension entirely, exporting to Markdown or JSON and searching across notes are the other two Pro features.

Turning sync on

Sync, along with the rest of the Pro feature set, is available during FreelyMemo's 7-day free trial — no credit card needed to try it. To keep using it afterward, FreelyMemo Pro is a one-time $10 payment, not a subscription, covering both your Chrome and Firefox seats. Full details are on the pricing page.

Install FreelyMemo on both browsers, turn sync on with your license key, and your notes will start showing up on both within about a minute.

If you only ever use one browser, none of this changes anything about how FreelyMemo behaves for you — sync is additive, not a requirement. It exists for the specific case of wanting the same notes in more than one place, encrypted the whole way there.